The religious leaders of Jesus’ day taught that if you were not to break the Law of
Moses, the heart of which was the ten commandments, you had to avoid everything that
might lead to breaking the Law. If you were to observe the Sabbath, you should know
how far you could walk on the Sabbath or to what extent preparing food violated the
Sabbath rest. For this purpose, secondary rules were added, as a “hedge around the
Law,” to protect one from breaking the commandments.
With time, the secondary rules assumed their own importance. When Jesus was
criticized for opposing the Law. Jesus answered, “Do not think that I have come to
abolish the law and prophets, I have come not to abolish them but to fulfill them.”
Jesus did not diminish the commandments. He insisted that it is not enough to keep the
commandments externally: we have to keep to keep them internally. It is not enough not
to kill: we cannot speak abusively to others or even to think evil thoughts about others. It
is not enough not to commit fornication we should not give in to sexual phantasies.
Jesus does not make the commandments easier. He takes them more seriously than
his contemporaries. It is easier to wash cups and not walk distances on the Sabbath
than it is to turn away from angry and lusting thoughts. Jesus gets to the heart of the
commandments, teaching us to love God with our whole hearts, our whole souls, our
whole strength and minds and to love our neighbors in a good way.
Jesus’ teaching is completely the opposite of what is displayed on television, in videos
and the internet and even the way that many people talk. To choose to live in a chaste
way and be a peacemaker is the opposite of many of contemporary communications.
Jesus teaches us to love others in a good way. The two words, “love” and “sex” are
used together. People speak of “making love,” when the sexual relations really aren’t
love. They are people using other people without commitment to the other person.
Jesus is not against sexual relations. The book of Genesis says, “A man leaves his
father and mother and clings to his wife and the two of them become one body.” Jesus
adds, “What God has brought together, let no one separate.”
What are young people supposed to do until they actually find the right person and
make that life commitment to them? All of us are called by Jesus to love others in a
good way. How do we control our impulses because the sexual drive and the power of
anger are so strong?
According to the Gospels, Jesus resisted social pressure to regard secondary rules with
the same importance as the commandments. St. Thomas Aquinas explains that Jesus
refused “to abstain from doing even works of kindness on the Sabbath, which was
contrary to the intention of the Law” (1a2ae. 107, 2, ad 3).
 
As we can see in the Sermon on the Mount, Jesus asserted that the Commandments
must be kept. St. Thomas Aquinas affirms that Jesus fulfilled the Law “by explaining the

true sense of the Law” (1a2ae. 107, 2). He went further than the Law itself because He
insisted that the Commandments must be kept from the inside out, including our interior
thoughts and dispositions (Commentary on the Gospel of St. Matthew, 5).
 
It is not enough not to kill; we should not hate or grow angry. It is not enough not to
commit adultery; we should not lust interiorly.  Thomas explains:
 
The Law fixed a limit to revenge, by forbidding men to seek vengeance
unreasonably: whereas Our Lord deprived them of vengeance more completely
by commanding them to abstain from it altogether. With regard to hatred of one’s
enemies, He dispelled the false interpretation … by admonishing us to hate, not
the person, but his sin… (1a2ae. 107, 2).
 
Has Jesus made keeping the commandments more difficult? Thomas comments: “The
precepts of the New Law are more burdensome than those of the Old; because the New
Law prohibits certain interior movements of the soul, which were not expressly
forbidden in the Old Law in all cases” (1a2ae. 107, 4).
 
Is it actually possible not to be angry or to hate or not to feel sexual attractions?
Controlling our thoughts or feelings doesn’t come easily. Thomas distinguishes between
the feelings that are “a movement of the mind, which is either sudden or with
deliberation” (Commentary on the Gospel of St. Matthew, 5). We are less responsible
for sudden and spontaneous thoughts or feelings but we are responsible if we nurture
them with deliberation.
 
St. Thomas believes that we are able to give order to the spontaneous thoughts and
feelings by developing good habits, which are the virtues. According to Thomas, virtue
enables believers to act well: “to act thus is difficult for a man without virtue but through
virtue it becomes easy for him” (1a2ae. 107, 4).
 
Some virtues are simply given by God. Very often, the virtues, similar to other habits,
are built up by repeating an action. We need God’s help in repeating these actions as
well. When we build up the virtues, we act in a virtuous way, “promptly and with
pleasure” (1a2ae. 107, 4).
One way of confirming the habit of virtuous actions is to take responsibility when we
have acted otherwise. Thomas echoes Augustine’s advice that we prepare to approach
God at the altar of the church or at the altar of our heart, “by prostrating yourself humbly
in the presence of the One to whom you are about to offer; if he [the injured person] is
present, he must be returned to your love by seeking pardon from him” (Commentary on
the Gospel of St. Matthew, 5).
Thomas recognizes that the person may not have offended us justly: “He does not add
‘justly’, He makes it plain that even the one who suffered the injury ought to seek
friendship (Commentary on the Gospel of St. Matthew, 5).

Thomas recalls the words of the Old and New Testaments: “You shall not hate your
brother in your heart” (Lv 19:17) and “Do not let the sun go down on your anger” (Eph.
4:26).
For Thomas, we need to be concerned about the effect that harboring negative feelings
has on ourselves: “… not only because we harm the neighbor, but because we give the
unclean spirits room within us for doing what they will” (Commentary on the Gospel of
St. Matthew).
Thomas turns to the advice of St. John Chrysostom: “If you have offended by thought,
be reconciled by thought; if by words, by words; if by deeds, by deeds” (Commentary on
the Gospel of St. Matthew, 5). At times, we need to apologize by words, at times by our
actions but, at other times, we need to make peace in our thoughts when we have
sinned against another by thought.
According to Thomas, the New Law, given by Jesus, is not a revised list of updated
regulations but an inner principle that enables us to do good. Thomas states: “The New
Law consists chiefly in the grace of the Holy Spirit, which is shown forth by faith that
works in love” (1a2ae. 106, 1, 2; 108, 1).
Ultimately, we need to pray for a greater love because love enables us to act in a good
way. Thomas frequently returns to Augustine’s explanation of 1 John 5:3: “His
commandments are not heavy.” Augustine wrote: “They are not heavy to the man who
loves; whereas they are a burden to him who loves not.”
Denis Vincent Wiseman, O.P.
The quotations from St. Thomas Aquinas’ Commentary on the Gospel of St. Matthew
were done by R.F. Larcher, O.P.